Black sulfur dye and process of making same.



, UNITED STATES PATENT OFFICE.

IVAN LEVINSTEIN AND CARL MENSCI-IING, OF MANCHESTER, ENGLAND, ASSIGNORSTO LEVINSTEIN, LIMITED, OF MANCHESTER, ENGLAND.

BLACK SULFUR DYE AND PROCESS OF MAKING SAME.

SPECIFICATION forming part Of Letters Patent N 0. 702,369, dated JunelO,1902.

Applioationfilecl October 5,1901- Serial No. 77,628. (Specimens) To allwhom it may concern.-

Be it known that we, IVAN LEVINSTEIN, a citizen of the British Empire,and CARL MENSCHING, Ph. D., a citizen of the German Empire, bothresiding at Manchester, in the county of Lancaster, England, haveinvented certain new and useful Improvements in Black Sulfur Dyes andProcesses of Making Same, of which the following is a full, clear, andexact description.

In the specification of Letters Patent N 0. 655,659 there is describedthe manufacture of black coloring-matters directly dyeing cotton byheating dinitrophenol in an aqueous solution, together with sulfur andthe sulfid of an alkali metal. In the specification of German LettersPatent No. 125,586 there is also described the manufacture of acoloring-matter by treating picric acid in a similar manner.

We have discovered that black coloringmatters totally different fromthose produced as described in the United States and Germanspecifications above cited are produced by heating with sulfur and thesulfid of an.

alkali metal in an aqueous solution, either at the boiling-point or at ahigher temperature and with or without the addition of a metal--such,for example, as zinc-or of a salt of a heavy metal, mixtures in variableproportions of either dinitrophenol or of picric acid or of mixtures ofthese two substances or the corresponding amido or nitroamidoderivatives of phenol, such as picramic acid, with oxyazobenzene or itshomologues or substitution products. This reaction is remarkable, sinceoxyazobenzene when heated in aqueous solution with sulfur and a sulfidof an alkali metal yields a substance of no tinctorial value.

The following examples illustrate in what manner we may carry ourinvention into effect. It is to be understood that the proportionsspecified in the examples may be varied considerably.

Example I: Eighty-five kilos of crystallized sodium sulfid, 18.4 kilosof sulfur, and fifty liters of water are boiled together until thesolution is clear. There is then gradually added to it a mixture of 18.4kilos of dinitrophenol and 9.4 kilos of oxyazobenzene, and the productis boiled in a reflux apparatus until the formation of thecoloring-matter is complete. The coloring-matter is precipitated bymeans of mineral acids or of common salt or of sodium bicarbonate or bythe introduction of a current of air. It easily dissolves in a hotsolution of sodium sulfid, to which it gives a greenish black color.This solution dyes unmordanted cotton blueblack shades, while thecoloring-matters obtained from dinitrophenol or from picric acid alonedye blacks of a dull and red shade.

Example II: Eighty-five kilos of crystallized sodium sulfid, 18.4 kilosof sulfur, and fifty liters of water are boiled together, and there isgradually added a mixture containing 22.9 kilos of picric acid, 9.2kilos of oxyazobenzene, and 4.5 kilos of zinc-dust. The whole mixture isheated in a reflux apparatus until the formation of the coloring-matteris complete. The black coloring-matter thus produced is separated asdescribed under Example I. It easily dissolves in a hot solution ofsodium sulfid, formingagreenishblack solution, which dyes unmordantedcotton a bright red-black shade, which possesses a full plum overhandappearance resembling that produced by logwood.

Example III: Eighty-five kilos of crystallized sodium sulfid aredissolved in fifty liters of water and 18.4 kilos of sulfur are addedthereto. There is then slowly added a mixture of 19.9 kilos of picramicacid and 9.2 kilos of oxyazobenzene, and the mixture is boiled until theformation of the coloringmatter is complete. The coloring-matter isprecipitated, as described under Example I, and is a dyestuif whichproduces on unmordanted cotton similar shades to those produced by theproduct of Example II.

The process may be carried out either by boiling in an open vesselprovided with a reflux-condenser, or a sufficient dilution may bemaintained by the addition of water from time to time.

By varying the proportions valuable blacks are obtained which dyeunmordanted cotton shades varying from bright red-black to violet andgreenish blacks, as is shown by the Having now particularly describedour invention, We declare that what We claim is- 1. Thehereinbefore-described process for the production of black sulfidcoloring-matters which consists in heating in the wet Way and with thecondition of dilution maintained, the hereinbefore-describednitrophenols with oxyazobenzene and with sulfur and a sulfid of analkali metal, substantially as set forth. 2. As new black sulfurcoloring-matters, a black powder produced byheating in the wet way andwith the condition of dilution maintained, the hereinbefore-describednitrophenols with oxyazobenzene and with sulfur and a sulfid of analkali metal, which powder is insoluble in water, insoluble in alcohol,soluble in a solution of sodium sulfid with a greenish-black color,soluble in concentrated sulfuric acid and precipitated therefrom ondilution with water, and dyes unmordanted cotton shades varying frombright red-black to greenish black.

In Witness whereof we have subscribed our signatures in presence of twowitnesses.

V IVAN LEVINSTEIN. CARL MENSGI-IING. Witnesses:

WILLIAM E. HEYs, ARTHUR MILLWARD.

